Bradley Merrill Thompson, a lawyer with the firm Epstein Becker & Green specializing in health policy, said companies are legally required to preserve such records for two years after they are created. CMS enforces this rule under Clinical Laboratory Improvement Amendments, or CLIA, which are the set of standards applied to clinical lab testing companies like Theranos.

Thompson said it's "interesting" that the former employee allegedly filed the complaint with CMS, rather than the U.S. Food and Drug Administration. It's not clear in this case, he explained, whether the FDA or CMS would have jurisdiction to take legal action if the claims prove to be accurate.